ABSTRACT
This chapter aims to establish a curve for the so-called spontaneous recovery of an extinguished conditioned reaction and to do some preliminary work on a systematic investigation of certain relatively neglected phenomena which seem to appear during the non-reinforced trials involved in extinction. Eighteen albino rats were thoroughly trained to run a short alley for food and then given a total of 1960 non-rewarded trials in that alley. During the succession of non-rewarded trials there was an increase in the time required to run the alley and in the amount of agitated behavior exhibited while running the alley. Tests following rewarded trials demonstrated that the curves secured in the experiment represent a recovery from the effects of extinction rather than some more general tendency for the intervals to produce an increase in the speed of running. The relationship between rate of administration and rate of extinction should be dependent upon the rate of recovery during the interval between trials.
